A transmission method and a transmission apparatus in which a plurality of AV-devices are connected by a network using an IEEE 1394 system bus line and video data, audio data and other data are transmitted between the above devices have been put into practical use. In the case of the IEEE 1394 system bus line, there are available an isochronous transfer channel for transmitting data of a large capacity such as video data and audio data and an asynchronous transfer channel for transmitting data such as control commands so that these data can be transmitted in the mixed state.
Details of a format for transmitting audio data (music data) by the IEEE 1394 system bus line is disclosed in [Audio and Music Data Transmission Protocol]. This [Audio and Music Data Transmission Protocol] is laid open in 1394 TRADE ASSOCIATION.
Conventional audio data prescribed such that it should be transmitted according to the above format is only general digital audio data in which a sampling frequency is a constant frequency such as a constant frequency of 44.1 kHz and one sample is formed of 16 bits or 24 bits. On the other hand, there have been proposed a variety of new digital audio data formats capable of improving a tone quality of reproduced sounds much more. Various types of multichannel audio data formats capable of reproducing multichannel audio data over 2 channels have been proposed. Hence, there exist a large number of digital audio data formats.
The above IEEE 1394 system bus line, however, cannot take the transmission of audio data of such new format into consideration. Hence, it is difficult to transmit such audio data according to the present format.
When audio data is transmitted, there is a demand that not only audio data itself but also data accompanied with copy control information or the like should be transmitted. The transmission of such accompanying data is not taken into consideration depending upon a format of transmitted audio data. Hence, some countermeasure should be made.